1. Field of the Invention
The present invention relates to an improved bracket for a giga- bit interface convertor. More particularly, the bracket provides an improved grounding to a PCI card, daughter card, motherboard and the like.
2. Background
A bracket provided in accordance with the present invention is designed to contain a universal giga-bit interface convertor (GBIC) module. A giga-bit interface convertor is a high-speed data transfer switch that can be used to interconnect work stations, main frames, supercomputers and storage devices. It can be employed at various locations in a computer network where giga-bit data is transferred. A high-speed data transfer switching is used in many applications such as Video on Demand and interactive video, which require faster access to large data storage systems such as DASDs and RAIDs.
FIG. 1 shows an example of a network where giga-bit interface convertors are employed. A mass storage 1 may be DASD/RAID mass storage. The mass storage 1 is connected to a server 3. Data transfer rate is in the order of Gbits/sec. For instance, the rate may be 1.0625 Gbits/sec. with provisions for 2.125 Gbits/sec. and 4 Gbits/sec. The server 3 is in turn connected to a hub or switch 5 by a giga-bit interface convertor module 9. The giga-bit interface convertor module 9 plugs into a guide assembly or bracket (FIG. 2) provided on a motherboard 6. In place of a motherboard, any printed card may be employed. A plurality of work stations 7 are provided to connect with the hub 5 for giga-bit data transfer.
FIG. 2 shows a giga-bit interface convertor module 11, a bracket or guide assembly 15 and an interface expansion card 17. The giga-bit interface convertor module 11 shown here is of a type which employs twenty-position straddle mount plug 19 on one end and a duplex copper interface 21 on the other. It is noted that the interface can be fiber optics rather than copper. The plug end 19 is inserted through an opening 23 in the front of the guide assembly 15 until the plug connects to a receptacle 29. Simultaneously, detents on the giga-bit interface convertor module 11 snap into place on the guide assembly 15. A pair of channels 25 are defined on longitudinally extended sides of the module 11 and a complementary pair of bars 27 are provided on the interior sides of the guide assembly 15 for mating with the channels 25 so that the module 11 may be suitably aligned and guided toward the rear of the guide assembly 15. The plug end 19 of the module 11 is received by the receptacle 29, which in this case is a twenty-position right-angle receptacle, provided on the interface expansion card 17.
As shown in FIGS. 3-5, the guide assembly 15 has an integrally formed housing 16, which is made of thermoplastic. When the guide assembly 15 has no module plugged into it, a self-closing metallic dust door 31 shields the interior of the interface expansion card 17 from the exterior environment. The dust door 31 is spring-biased with an expansion card spring 100 (FIG. 5) provided on one side of the guide assembly 15. Upper and lower grounding clips 33 and 35 are provided at the opening 23 of the guide assembly 15 to make contact with both the module 11 and the interface expansion card 17. The upper and lower grounding clips 33 and 35 are in turn provided with a plurality of tabs 32, 34 (see FIG. 3) which are slightly raised from the rest of the grounding clips 33, 35. Although this is intended to provide a ground path as explained below, only a limited and partial ground path is established.
The guide assembly 15 employs integrally-formed hold-down latches 37 to fit in corresponding hold-down latch apertures 38 formed in the interface expansion card 17. To provide alignment and stability, the guide assembly 15 also employs two pairs of alignment knobs 39 adjacent the hold-down latches, which fit in corresponding knob apertures 41 formed in the interface expansion card 17. Further, two guide assemblies, each of which is identical to the guide assembly 15, may be mounted side-by-side on interface expansion card 17.
The above-described conventional guide assembly 15, however, does not provide grounding to the interface expansion card 17 and only a very limited grounding to the giga-bit interface convertor module 11 and to the interface panel, and requires a significant amount of re-engineering before it can be used in a commercial environment. For instance, an extra gasket must be provided to aid the dust door 31 with its electromagnetic interference attenuation. The guide assembly 15 has problems with electromagnetic interference emanating from the plugged-in module 11 because the guide assembly 15 does not adequately contain electromagnetic interference. Specifically, the giga-bit interface convertor, module 11 needs a high frequency, low impedance path to ground, and the opening, through which the giga-bit interface convertor module 11 is accessible to the user, needs to be shielded when the giga-bit interface convertor module 11 is not installed.